Explosive-engine.



- No. 739,220. y PATENTED SEPT. 15, 1903.; 1.11. REDPIELILV EXPLOSIVB'BNGINB.

APPLICATION FILED NOV. 21, 1902.

N0 MODEL.

lf////////'/// .l ///////////m w *I W /0/v Wifgzgzs' l .y Igegm'.. I

I a/ l f r l UNITED seiajfaI Patented September 15, 1903.l l

JOHN H'. REDFIELD, OF lSPOKANE, WASHINGTON.

`EXPLOSlVl-ENGINE.

SPECIFICATION forming part of Letters Patent No. 739,220, dated September 15, 1903. Application filed November 21. 1902. Serial No. 132,318.- (No model.)

this character cannot ordinarily be employed,

owing to the poisonous exhaust and the c o'n-v sequent vitiation of the air.

An object of the invention is to provide for the cooling of the cylinder by entirely inclosing the crankchamber and employing it as fa suction -inlet chamber of which the lower or inner face of the trunkpiston forms the operative element, the air'to cool the cylinder being drawn in through an opening in the upper cylinder-head and thence through ports or passages situated in the wall of the cylinder and into the crank-chamber, from whence it is discharged, together with the products of combustion, through a pipe leading to the outer air. Y Y y A still further object of the invention is to provide for the conveyance of the poisonous exhaust from the engine to the mouth of the mine, tunnel, or other place where the engine is located.

With these and other objects in view the invention consists in the novel construction and arrangementV of parts hereinafter described,illustrated in the accompanying drawings, and particularly pointed out in the appended claims, it being understood that various changes in the form, proportions, size, and minor details of the structure may be made without departing from the spirit or sacriiicing anyV oi' the advantages of the invention.

In the accompanying drawings, lFigure 1 isV a longitudinal sectional elevation of a gasengine constructed Yin accordance with myA invention. "Fig 2 is a sectional plan view of the same on the line 2 2 of Fig. 1. Fig. 3 is to indicatecorresponding parts throughout the several figures ofthe drawings.

The engine is provided with a ,supportingy base 10, on which is bolted a crank-chamber 1l, having suitable bearings for the support of a crank-shaft 13, having one or more flywheels 14, eitherv or both of which may be used as belt-wheels. On top of the crank- 6o casing is bolted acylinder 15, in which is a' trunk-piston 16, connected in the usual manner to the crank-shaft.

' At one side of the cylinder is bolted avalvechamber 17, formed in the usual manner and v provided with inlet and exhaust valves, of

which the stems areJ indicated at 18 and 19, respectively. This portion of the structure may be similar to `that ordinarily followed in the construction of four-cycle engines and 7 o forms no part ofthe present invention. Thev explosive mixture is fed to the valve-chamber 17 through a supply-pipe 20, and the exhaust is led throughy a pipe- 21 to a muffler 22, Which may be of any ordinary construction,

Vand from thence to the outer air in a manner more particularly described hereinafter.

In the lupper portion of the explosive-chamber is an insulated sparking plug 24, of the usual construction, and which maybe con- 8o vnected to a source of electrical energy in 4the ordinary manner. In the side of the explosion-chamber isa bearing for the reception of a rock-shaft 25, to the inner end of which is I secu-reda movable contact 26, which forms the opposing terminal of the circuit, the separation of the two lelectrodes resulting in the formation of an arcv and the. spark igniting the explosive mixture in the usual manner.

. The sparking and the valve operating 9c mechanisms form no part of the' present` invention and may be operated in any ordinary manner.

In order to cool the cylinder, I provide in the cylinder-head a port or passage 90, closed by an inwardly-opening checkvalve 91. This opening. communicates with a number of ports or passages 92, formed in the cylinder-head and communicating' in turn with 4verticallydisposed ports 93,formed in the wall of the cylloo v of the gases a partial vacuum will be created in the crank-chamber and air Will be drawn through the opening 90 and downwardly through the ports 92 and 93 to cool the cylinder. This air enters the crank-chamber, and on the downstroke of thel piston is forced out through a pipe 95, having an outwardlyopening check-valve 96. The pipe 95 is led directly to the outer air, so that a portion of the air in the tunnel or mine is constantly being pumped to the surface of the ground and Vmust be replaced by fresh air from Without,

thus creating a natural circulation and at all times keeping up a constant supply of fresh air.,

The exploded gases are led from the lower portion of the muli-ler through a pipe97 to the air-exhaust pipe 95, the connectingpipe 97 being' provided with an outwardly-opening check-valve 9S, so that none of the exploded gases can enter the tunnel or mine and vitiate the air. As a further means of inducing the circulation the muffler may be provided with one or more pipes 99, having inwardly-opening cheek-valves 100 and a controlling-valve lOl to permit the flow of a quantity of fresh air into the muffler, there to mingle with the exploded gases and be carried of f through the air-exhaust pipe 95.

It will of course be understood that the positions of the cheek-valve and discharge-pipe maybe transposed and the air drawn into the crank-chamber direct on the upstroke of the piston and thence discharge upwardly th rough the passages in the walls of the cylinder and forced out through the discharge-pipe connected to the top thereof, and this change may be made without in any manner departing from my invention.

Having thus described my invention, what I claim isl. A Ventilating system for mines, tunnels, shafts and t-he like comprising a gas-engine acting in part as an air-pump to induce the ow of a current of vitiatcd air from the mine through the cylinder-jacket and thus effecting the heating of the air by radiation and conduction from the heated cylinder, a discharge-pipe leading to the outer air and serving to conduct the vitiatcd and heated air thereto, and a connecting-pipe for conveying' the exhaust from the engine to said pipe to further assist the heating operation and by its force or impact aiding in the movement of the air toward the outlet end of said pipe. l

2. A Ventilating system for mines, tunnels, shafts and the like, in which a gas-engine is employed for the operation. of drills and other tools, said gas-engine acting in part as an airpump and inducing the current of vitiatcd air from the mine through the cylinder-jacket to thereby coolA the cylinder and at the same time heat the air by conduction and radiation from the cylinder, a discharge-pipe leading from the engine to the outer air and through which said Vitiated and heated air is conducted, connections between the exhaust and a muffler, an air-entrance pipe leading to the muffler to conduct thcreinto vitiatcd air from the mines, said pipe being provided with a check-valve, and a connecting-pipe between the .muffler and the discharge-pipe to convey away the exhaust and the air entering the muflier, the discharge through the pipe being effected partly by the force or impact of the exhaust, partly by the pumping action of the gas-engine, and partly by the natural tendency of the heated air to rise to the surface end of the pipe.

3. In an apparatus of the class described,

a gas-engine having a cylinder and provided with a crank-chamber, air-passages leading' through the walls of the cylinder to form a cooling-jacket therefor, the inner side of the piston ofthe engine acting in connection with the crank-chamber to form a pump for in ducing the flow of vitiatcd air from a mine through the cylinder-passages to thereby cool the cylinder and at the Sametime heat the air by radiation and conduction from the heated cylinder, an air-discharge pipe leading from the engine to the outer air and provided with an inwardly-closing check-valve, a muffler, a connecting-pipe between the muffier and the exhaust-port of the engine, and a second pipe also containing a check-valve and connecting theV muffler to the air discharge pipe, the connection between the two pipes being at a point beyond the check-valve of the main pipe, substantially as specified.

In testimony that I claim the foregoing as my own I have hereto aflixed my signature in the presence of two Witnesses.

JOHN II. REDFIELD. lVitnesses:

ALEX. A. ANDERSON, Il. RANAHAN. 

